The present invention relates to a method for controlling ecto-parasites of animals. In detail, the present invention relates to a method for controlling ecto parasites of animals wherein 1-(2,6-difluorobenzoyl)-3 -[2-fluoro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]urea (hereinafter, recited as Compound #1) is applied to the said animals.
Ecto-parasites have-been responsible for the transmission of disease. Fleas have been a particular problem because of their ability to completely infest an environment. The female flea lays her eggs on the host animal after mating. The eggs are able to fall off the host and be distributed to the host's environment. By this mechanism, the eggs are able to cover a larger area.
It is disclosed in Japanese patent publication (laid-open) No. 2-138247 that Compound #1 has an insecticidal activity. The publication discloses that benzoylurea compounds including Compound #1 in the publication are excreted as they are and therefore, can control the larvae and eggs of such insects like houseflies that breed in the excretion of domestic animals when they are applied to the domestic animals orally.
It is disclosed in U.S. Pat. No. 4,089,975 that benzoylurea compounds such as 1-(2,6-difluorobenzoyl)-3 (4-trifluoromethoxyphenyl)urea (hereinafter, recited as Compound A) and 1-(2,6-difluorobenzoyl)-3-[4-(1,1,2,2-tetrafluoroethoxy)phenyl]urea (hereinafter, recited as Compound B) can also be used for controlling insects which inhabit in excretion of domestic animals.
On the other hand, Japanese patent publication (laid-open) No. 63-72631 discloses a method for defending dogs or cats from re-infection of fleas by applying juvenile hormone like chemical compounds, triazine derivatives that regulate the growth of fleas and benzoylurea derivatives (specifically, N-3-(5-trifluoromethylpyridin-2-yl)phenyl-N'-benzoylurea derivatives) that regulate the growth of fleas to dogs or cats. However, the effectiveness of the method generally do not last a sufficient amount of time.